<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        //alert、prompt
        let value = "helloworld";
        console.log("this is debug test...:"+value);

        var num = 12 ;

        console.log("num:"+num);

        //重复的声明变量
        //let value = 12 ; 
        let num1,num2,num3 = 10 ; 
        console.log(num1,num2,num3);
        var obj = new Object();
        obj.name = "zhangsan";
        obj.age = 15;
    </script>
</body>
</html>